bjohnson,
How is the condition of your batteries, and the alternator? Do you have a voltmeter in the truck? I was having issues with my alternator, the factory unit went Tango Uniform, replaced it with a reman from NAPA, that reman went Tango Uniform, replaced it with another reman, Tango Uniform, and now they have swapped out a new for the second TU reman. When the first reman went TU the battery light did not come on, but I had a cigarette lighter plugin volt meter (I know not the best but better than nothing) but at ~ 10 volts the stereo shut down, and at ~ 9 volts the instrument cluster shut down, no indications at all, Speedo, Tach, idiot lights, it was like the truck was shut off. The engine was still running but the all the in-dash electronics shut down. When the second reman went TU, the battery light did come on, and I was at ~ 11.5 volts at the time. You may have a supply problem of some type. Do you have any trouble getting the truck to start, or keeping the batteries charged?